Fuel burner nozzle and assembly



Aug. 7, 1956 F. F. SCHLITT 2,

FUEL BURNER NOZZLE AND ASSEMBLY Filed Oct. 51, 1951 INVENTOR. FLOYD f?SCHL/TT BY E/CHEK WA 775, EDGEEI'ON a M-wQvA/Y United States Patent FUELBURNER NOZZLE AND ASSEMBLY Floyd F. Schlitt, Elyria, Ohio ApplicationOctober 31, 1951, Serial No. 254,067

7 Claims. (Cl. 158-115) The present invention relates generally to fluidfuel burner assemblies and is more particularly concerned with a novelburner nozzle and a new burner nozzlepilot assembly.

The problem of igniting fuel at the nozzle of a fluid fuel burner hasreceived the attention of many workers skilled in the art over a longperiod of time. For some purposes and in case of some types of burners,the problem has been entirely disposed of through the invention ofthoroughly satisfactory ignition means. In other instances, however, theproblem is still very much in existence because heretofore no one hasbeen able to devise a completely satisfactory solution. For example, noignition means and burner nozzle combination which is satisfactory fromthe standpoint of relatively long, trouble-free service life iscommercially known today. In the usual gas conversion burnerconstruction which is designed for home use, for instance, the servicelife of the pilot burner is limited to a relatively short period so thatthis item constitutes an important economic factor in the use of theseburners. In these conversion burners it is, of course, absolutelyessential from the safety standpoint and because of the laws governingthe design and operation of these devices, that the pilot burner belocated where the pilot flame will always be in a position relative tothe main burner nozzle to assure ignition of gas issuing therefrom. Thisrequirement has always carried with it the necessity for locating thepilot burner in a zone of high temperature closely adjacent to the mainburner nozzle outlet opening. As a result, damage or destruction of thepilot burner occurs in a short period of use.

In accordance with my invention all the requirements, legal andotherwise, as to the installation and operation of gas conversionburners may be completely satisfied, while at the same time their pilotburners are removed from the relatively high temperature zone of theirprior art environment. In other words, in accordance with thisinvention, the useful life of the ordinary pilot burner can be greatlyprolonged without impairing the function or the efiiciency of the pilotburner in the ignition of the combustible fuel mixtures deliveredthrough the main burner nozzle outlet.

As another advantage of this invention, gas-air mixtures at the mainburner nozzle may be ignited by the pilot burner even though the pilotflame is extinguished. Thus, in the newer type of pilot burnersemploying thermocouples in the head portion and having a plurality ofrelatively small openings for escape of fuel to support small secondarypilot flames or theimocouple heating flames, the main burner nozzle maybe ignited by these small flames in the absence of the main pilot flameitself. With the advent of this newer type of pilot burner, some citieshave enacted or are about to enact codes requiring installation of thesepilot burners in such a way that the ignition result will be obtainedintheabsence' of the main pilot flame. But for this invention, it wouldbe necessary under these codes to place the pilot burner i ice at leastpartially across the outlet port of the main burner nozzle, therebysubjecting the pilot burner head portion to even more severe serviceconditions than it has had to endure in the earlier types ofinstallation.

As still another advantage of this invention, the length of pilot flamerequired to assure ignition of combustible mixtures of fluid fuelissuing from the main burner nozzle can be substantially reducedregardless of the width of the outlet end wall of this nozzle withoutmoving the pilot burner closer to the nozzle outlet and into the highertemperature zone surrounding that outlet. This means that a more stableand dependable pilot flame can be used than has been possible heretoforeunder the same general circumstances. It also means that ignition can bedependably obtained by means of the thermocouple heating flames of thepilot, particularly in those instances where a burner nozzle of thinwall section, such a nozzle shell formed of thin pressed steel, isengaged.

Those skilled in the art will gain a further and better understanding ofthis invention on consideration of the following detailed description ofthree preferred embodiments of this invention, reference being had tothe drawings accompanying and forming a part of this specification; inwhich:

Fig. 1 is a side elevational view of a burner nozzlepilot burnerassembly in which the nozzle is shown in cross-section and the pilotburner is disposed in novel relation thereto in accordance with thisinvention;

Fig. 2 is an end view of the assembly of Fig. 1, showing how the pilotflame is directed by the pilot burner into the main burner nozzle;

Fig. 3 is a view like Fig. 1, but shows an alternate form of burnernozzle of this invention;

Fig. 4 is an end view of the Fig. 3 assembly; and,

Fig. 5 is a fragmentary, side elevational view of an assembly of a pilotburner and another form of burner nozzle of this invention, said nozzlebeing shown in crow section.

Briefly, a fluid fuel burner nozzle of the present invention comprises ahollow body having a side wall and inlet and discharge ports at itsopposite ends, this side wall being provided with a slot extending fromthe discharge port generally longitudinally of the body toward the inletport. More specifically, in a preferred form my novel burner nozzlecomprises a shell having fuel inlet and discharge ports at its ends, anozzle inside the shell having an inlet portion merging with the shellinlet and outlet portion spaced from the shell to define an open chamberin communication with the shell and nozzle outlets. The wall of thisinner nozzle has an aperture establishing communication with theinterior of the inner nozzle and the said open chamber, and the shellhas a slot which extends from the discharge port generallylongitudinally toward the inlet port.

The novel assembly of this invention accordingly may be defined ascomprising a fluid fuel burner nozzle as defined above, and a burnerpilot element having a pilot flame nozzle adjacent to the burner nozzleshell to direct a pilot flame into the open chamber in the said shellthrough the longitudinally extending slot provided for that purpose inthe shell.

Referring to the drawings, in Fig. l a burner nozzle N and a pilotburner P are shown in a normal assembled relation, according to myinvention. Burner nozzle N comprises a generally cylindrical shell 10having an inlet port 12 at one end and an outlet port 14 at the otherend, the outlet port being defined by an annular end wall portion 15.The nozzle has an annular inner wall portion 17 of generally conicalshape which is integrally formed with the shell and merges therewithnearer inletport 12 than outlet port 14 to define an inner nozzle. Innerwall 17 terminates Within shell 10 adjacent to but spaced from end wall15 and outlet port 14 and itself defines a discharge or outlet port 19which is coaxial with ports 12 and 14 but of reduced diameter comparedto them. Thus, an annular chamber 20 is defined within shell forwardlyof the inner wall 17 and this chamber is open to the interior of theinner nozzle through port 19 of said inner nozzle and is Open to theatmosphere through outlet port 14. In addition, there is communicationbetween chamber 20 and the interior of the inner nozzle through fourapertures 22 through inner wall 17, these being spaced uniformly anddirected at an angle to the axis of shell 10 so that gases flowingthrough the nozzle N may be diverted in part through these apertures anddirected generally forwardly of the nozzle into chamber 20.

A slot 25 is provided in shell 10 and extends through a portion of endwall and longitudinally of the shell to a point adjacent to the junctionof inner wall 17 and the shell. Slot 25 is disposed in register with oneof the apertures 22 so that gas passing through this aperture intochamber will be directed toward slot 25.

In this Fig. 1 assembly, pilot burner P is disposed with its headportion 30 adjacent to shell 10 in such a position as to direct a pilotflame 32 into chamber 20 through slot 25, as illustrated in Figs. 1 and2. Head 30 also is so situated that gas flowing through slot will comeinto contact with thermocouple flames 33 thereof and be ignited therebyif principal pilot flame 32 is extinguished at the time.

In reference to the Fig. 3 assembly, the same pilot burner P is employedagain, but the burner nozzle 40 differs from nozzle N in certainrespects. Nozzle 40 is like nozzle N in that it comprises a shell 42having an inlet port 43 at one end and a discharge port 44 at the otherend, the latter being defined by an end wall 45. Shell 42. however, isof generally rectangular shape in transverse cross section, asillustrated in Fig. 4. Nozzle 40 has an inner wall portion 47 mergingwith the shell side walls between inlet and outlet ports 43 and 44 anddefining an inner discharge nozzle opening 49. Whereas inner nozzle wall17 of burner nozzle N is generally conical, inner wall 47 of this Fig. 3device is in the form generally of a four-sided pyramid. Also, innerwall 47 is provided with apertures 52 at its corners for flowing gasfrom the interior of the nozzle into a chamber 54 defined in the shellby inner wall 47 and end wall 45 and the side walls of shell 42. In oneof these side Walls approximately midway between two corners of theshell a slot 55 is provided and this slot extends through end wall 45 tothe nozzle discharge port 44. Slot 55 terminates short of the point ofmerger of inner wall 47 and the side of shell 42.

In this assembly, as in the Fig. l assembly, nozzle 40 and pilot burnerP are disposed adjacent to each other with head of the pilot burnerbeing situated to direct pilot flame 32 into chamber 54 for the purposeof igniting the fuel contained therein. It is also to be noted that byvirtue of the manner of the location and relation of pilot burner P tothe nozzle 40, gas issuing from nozzle through slot 55 will be ignitedby thermocouple flames 33 if flame 32 is not burning.

From the foregoing it will be understood that despite the structuraldifl erenccs between the two embodiments of the invention illustratedand described above, the novel advantages of this invention may beobtained because the function and etfect of these devices is generallythe same. In each instance, combustible mixtures of fluid fuel, such asnatural gas and air, atomized fuel oil or powdered coal and air,delivered to the burner nozzle and flowing through its inlet port,through the inner nozzle outlet portion, and through the apertures inthe inner wall of the nozzle into the open chamber in the nozzle shell,will be ignited by the pilot flame coming into contact with this fuel inthe nozzle shell and ignition of the burner is thus accomplished ineffect before the gas issues from the nozzle outlet port. This novelignition system and assembly accordingly has the advantages definedabove and the additional advantage of producing ignition more quicklyand perhaps more dependably than any gas conversion burner heretoforeknown. This latter result would be attributable to the fact that contactof flame with the gas to be ignited is effected within the nozzleitself, where concentration of the fuel is at an ideal level forignition and where the pilot flame will not be subject to strongcurrents of air which would tend to prevent ignitionproducing contactbetween the pilot flame and the burner fuel.

Referring to the embodiment of the invention illus trated in Fig. 5,here again, the assembly includes pilot burner P, suitably of the newerconventional design and construction described above, and a nozzle 60disposed adjacent to the pilot burner after the manner illustrated inFigs. 1 and 3. Nozzle 60 comprises a shell 61 having an inlet port 62 atone end and an outlet port 64 at the other end and has an annular innerwall portion 67 integrally formed with the shell and merging therewith.Nozzle 60 is of relatively thin wall section and is provided with a slot69 in an end wall 70. End wall 70, like end wall 45 of the Fig. 2device, defines outlet port 64 and an open chamber 72 is defined justinside this port through the cooperation of inner wall 67 and the shellside and end walls. Wall 67 defines an outlet port 68 and is providedwith slot-like apertures 74 spaced around port 68 which communicate withthe interior of the inner nozzle and open chamber 72 for the flow ofcombustible gas mixtures from within the inner nozzle into chamber 72,as described above. Slot 69 opens into discharge port 64 and also opensinto chamber 72 and it extends radially from port 64 to the side wall ofthe shell.

Pilot burner P is disposed beside nozzle 60 with its head portion 30extending forwardly of end wall 70 so that main pilot flame 32 isdirected lengthwise of slot 69 toward port 64 to assure ignition of thecombustible gas mixtures flowing from port 64 and the slot. It will bealso noted that by virtue of the advanced position of pilot burner head30 relative to nozzle 60, the thermocouple heating flames 33 directedtoward port 64 are s located as to be capable independently of ignitingcombustible gas mixtures issuing through port 64 and slot 69.

It will accordingly be understood that some of the more importantadvantages of this invention stated hereinabove are to be realizedthrough the use of this Fig. 5 assembly. It will be seen, for example,that ignition of combustible gas mixtures issuing from nozzle 60 will beassured in this assembly, regardless of whether flame 32 is effective,by virtue of the novel construction of nozzle 60 as described, and byvirtue of the novel relationship of this nozzle element with the pilotburner P, as shown.

Having thus described the present invention so that those skilled in theart may be able to gain a better understanding and practice the same, Istate that what I desire to secure by Letters Patent is defined in whatis claimed.

What is claimed is:

1. A burner nozzle comprising a shell having fuel inlet and dischargeports at its ends, a nozzle within said shell having an inlet portionmerging with said shell inlet and an outlet portion spaced from saidshell to define an open chamber in communication with said shell andnozzle outlets, the wall of said nozzle having an aperture establishingcommunication between the interior of said inner nozzle and said openchamber, and said shell having a slot in register with said aperture andextending from said discharge port generally longitudinally toward saidinlet port and terminating adjacent to the junction of the shell and theinner nozzle.

2. A burner assembly including a nozzle comprising a shell having fuelinlet and discharge ports at its ends. a nozzle within said shell havingan inlet portion merging with said shell inlet and an outlet portionspaced from said shell to define an open chamber in communi-.

cation with said shell and nozzle outlets, the wall of said nozzlehaving an aperture establishing communication between the interior ofsaid inner nozzle and said open chamber, and said shell having a slotextending from said discharge port generally longitudinally toward saidinlet port, and a burner pilot element having a pilot flame nozzledisposed adjacent to said shell to direct a pilot flame into the shellthrough the said slot.

3. A burner assembly including a nozzle comprising a shell having fuelinlet and discharge ports at its ends, a nozzle within said shell havingan inlet portion merging with said shell inlet and an outlet portionspaced from said shell to define an open chamber in communication withsaid shell and nozzle outlets, the wall of said nozzle having anaperture establishing communication between the interior of said innernozzle and said open chamber, and said shell having a slot in registerwith said aperture and extending through the shell to providecommunication between the chamber and the exterior of the shell, and aburner pilot element having a pilot flame nozzle disposed adjacent tosaid shell to direct a pilot flame into the shell through the said slotand into contact with a combustible fluid fuel mixture in said chamberand flowing in the direction of said slot from said aperture.

4. A burner assembly including a nozzle comprising a shell having fuelinlet and discharge ports at its ends, a nozzle Within said shell havingan inlet portion merging with said shell inlet and an outlet portionspaced from said shell to define an open chamber in communication withsaid shell and nozzle outlets, the wall of said nozzle having anaperture for permitting fuel to flow from the interior of the nozzleinto the chamber, and said shell having a slot opening into said openchamber in register with the aperture and terminating forwardly of thejunction of the shell and the inner nozzle wall, and a burner pilotelement having a pilot flame nozzle disposed adjacent to said shell todirect a pilot flame toward the said slot for igniting fuel gases in thechamber.

5. A burner nozzle comprising an outer shell having a fuel outlet portat its discharge end and a fuel inlet port spaced from the dischargeport and communicating therewith, an inner shell within the outer shellhaving an inlet opening communicating with the inlet port to receivefuel flowing through the nozzle toward said discharge port and having amain outlet opening in its outer end of diameter less than the diameterof said discharge port, the outer end of the inner shell being spacedaxially inwardly from the discharge end of the outer shell a distanceless than the diameter of the main outlet opening of the inner shell,the inner and outer shells cooperating to define in the nozzle acombustion chamber between the inner shell and the surrounding portionof the outer shell, said chamber communicating with the discharge portthrough the space between the outer end of the inner shell and thesurrounding portions of the discharge end of the outer shell, said innershell having an auxiliary aperture of diameter substantially less thanthe diameter of the said main opening communicating with the inletopening and with the combustion chamber for delivery of fuel into saidchamber, and said outer shell having a slot in its discharge end portionopening into the combustion chamber.

6. A burner nozzle comprising an outer shell having a fuel outlet portat its discharge end and a fuel inlet port spaced from the dischargeport and communicating therewith, an inner shell within the outer shellhaving an inlet opening communicating with the inlet port to receivefuel flowing through the nozzle toward said discharge port and having amain outlet opening in its outer end of diameter less than the diameterof said discharge port, said main outlet opening and discharge portbeing disposed substantially coaxially and the outer end of the innershell being spaced axially inwardly from the discharge end of the outershell a distance less than the diameter of the main outlet opening ofthe inner shell, the inner and outer shells cooperating to define in thenozzle a combustion chamber between the inner shell and the surroundingportion of the outer shell, said chamber communicating with thedischarge port through the space between the outer end of the innershell and the surrounding portions of the discharge end of the outershell, said inner shell having a plurality of auxiliary apertures ofdiameter substantially less than the diameter of the said main openingcommunicating with the inlet opening and with the combustion chamber fordelivery of fuel into said chamber, and said outer shell having a slotin its discharge end portion opening into the combustion chamber andextending to a point between the inner end of the combustion chamber andthe outer end of the inner shell.

7. A burner nozzle comprising an outer shell having an end Wall defininga fuel outlet port at its discharge end and a fuel inlet port spacedfrom the discharge port and communicating therewith, an inner shellwithin the outer shell having an inlet opening communicating with theinlet port to receive fuel flowing through the nozzle toward saiddischarge port and having a main outlet opening in its outer end ofdiameter less than the diameter of said discharge port, the outer end ofthe inner shell being spaced axially inwardly from the discharge end ofthe outer shell a distance less than the diameter of the main outletopening of the inner shell, the inner and outer shells cooperating todefine in the nozzle a combustion chamber between the inner shell andthe surrounding portion of the outer shell, said chamber communicatingwith the discharge port through the space between the outer end of theinner shell and the surrounding portions of the discharge end of theouter shell, said inner shell having a plurality of auxiliary aperturesof diameter substantially less than the diameter of the said mainopening communicating with the inlet opening and with the combustionchamber for delivery of fuel into said chamber, and said outer shellhaving a slot in its end wall opening into the combustion chamber andextending radially outwardly to the side of the outer shell.

References Cited in the file of this patent UNITED STATES PATENTS2,110,217 Gardner Mar. 8, 1938 2,533,143 Scharbau et al. Dec. 5, 19502,569,356 Turpin Sept. 25, 1951 FOREIGN PATENTS 683,439 Germany Nov. 6,1939 122,840 Australia Dec. 5, 1946

